Fix typos in clang

Found via codespell -q 3 -I ../clang-whitelist.txt
Where whitelist consists of:

  archtype
  cas
  classs
  checkk
  compres
  definit
  frome
  iff
  inteval
  ith
  lod
  methode
  nd
  optin
  ot
  pres
  statics
  te
  thru

Patch by luzpaz! (This is a subset of D44188 that applies cleanly with a few
files that have dubious fixes reverted.)

Differential revision: https://reviews.llvm.org/D44188

llvm-svn: 329399
diff --git a/clang/lib/Sema/SemaExprCXX.cpp b/clang/lib/Sema/SemaExprCXX.cpp
index f721479..74a6de5 100644
--- a/clang/lib/Sema/SemaExprCXX.cpp
+++ b/clang/lib/Sema/SemaExprCXX.cpp
@@ -5476,7 +5476,7 @@
   //      constraint that in the conversion the reference must bind directly to
   //      an lvalue.
   //   -- If E2 is an xvalue: E1 can be converted to match E2 if E1 can be
-  //      implicitly conveted to the type "rvalue reference to R2", subject to
+  //      implicitly converted to the type "rvalue reference to R2", subject to
   //      the constraint that the reference must bind directly.
   if (To->isLValue() || To->isXValue()) {
     QualType T = To->isLValue() ? Self.Context.getLValueReferenceType(ToType)